1. Field of the Invention
The present invention relates to a blade and, more particularly, to a splitting blade for splitting wood and, most particularly, to a multi-level splitting blade for splitting log sections into firewood having specific dimensions on any and all sides
2. Background Information
It is common practice to split log sections into smaller pieces to provide firewood that burns readily. This can be done manually with a mall and wedge, but the process is labor intensive and requires physical strength and endurance. In recent years, hydraulic cylinders have been used to push a section of log against a stationary wedge to split the log section into smaller pieces. The simple wedge has been replaced by devices having multiple cutting edges to divide the log section into smaller pieces with a single stroke of the hydraulic cylinder. Although numerous variations on the cutting wedge, also termed a splitting blade, have been developed, nearly all are subject to plugging and binding when attempting to split the log section into many smaller pieces in a single pass through the splitting blade.
Some examples of inventions involving devices or systems for cutting and splitting log sections for which patents have been granted include the following.
Schilling, in U.S. Pat. No. 4,353,401, describes a method and apparatus for splitting a log substantially along the grain into a plurality of sector-shaped segments. The apparatus comprises at least one sector splitter ring having a plurality of blades, a support for locating the splitter ring in a log movement path, means for pushing the log axially along a log movement path, a rotating backplate for supporting one end of the log being pushed along. The backplate is adapted to tilt and allow the backplate-supported end of the log to rotate as the log is pushed through the splitter ring. A guide means retains the floating backplate in the log movement path. The process comprises forcing one end of a log axially against and through at least one splitting blade. The other end of said log is in contact with a backplate that can tilt, and permits relative rotation between the log and the splitting blade, so that a split occurs in the log from the splitting blade substantially tends to follow the grain in the log. Multiple blades and spacers are shown in FIG. 9. All blades and spacers have radial spokes that meet at the center of the circular units.
In U.S. Pat. No. 4,371,020, Barnes et al. disclose a process for preparation of long wood strands. Long wood strands are required for the production of structural lumber products. These strands must be split, and a method of splitting logs into longitudinal-grain wood strands comprises the steps of radially splitting a log substantially along the grain of the log into a plurality of sectors shaped segments. Parallel splitting each of the sector shaped segments along the grain of the segments into a plurality of substantially parallel slabs, and further splitting each of the parallel slabs substantially along the grain of the slabs into a plurality of longitudinal-grain wood strands. Circular rings with spoke-like cutting blades are disclosed, which are similar to the Schilling patent.
Blomqvist et al., in U.S. Pat. No. 4,434,825, describe a firewood cleaving apparatus that comprises a number of cleaving irons situated in four different consecutive planes. A block of wood, forced down against the cleaving irons with the aid of a ram, is stepwise split into twelve billets. The irons in the first two planes split the block in four pieces along radial lines. The iron in the third plane is annular and yields eight pieces, while the irons in the fourth plane are radial, but cleave only the radially outer pieces that were separated from the radially inner pieces by the annular cleaving iron. Note, in particular, FIGS. 3 and 4 which detail the cleaving apparatus.
In U.S. Pat. No. 4,782,866, Valdez discloses a log splitting head, which includes a downwardly-sloped top portion having a sharpened leading edge in the form of a V-shaped cutting blade. Beneath the top portion, a first row of vertical cutting blades is provided, each including a sharpened leading edge. Also included is a second row of vertical cutting blades beneath the first row of blades and structurally similar thereto. Separating the two rows of blades is a medial portion having a sharpened leading edge. The sides of the splitting head include two vertical plates having sharpened leading edges. All of these components are arranged in a specific angular configuration designed to accomplish log splitting with maximum efficiency. The entire unit is adapted for attachment to a horizontal platform and enables the splitting of logs into uniformly sized sections.
Aikins, in U.S. Pat. No. 4,805,676, describes an adjustable feed ramp that supports the input end of a main frame at a height to tilt the main frame to correspond to the inclination of a log in process. Pulled into the machine by a winch line, the leading end of the log is gripped by vertical feed rolls on a pair of side squeeze arms, a horizontal feed roll on a top squeeze arm and then by a horizontal top feed roll of hourglass shape just ahead of a vertical transverse shear blade. In a first operation, the shear blade cuts less than entirely through the log and then moves away from the input end of the main frame, sliding the log, assisted by the feed rolls, farther into the machine. This movement pushes the leading end of the log through an adjustable splitter head assembly capable of splitting the leading end portion into two, three or six pieces, as desired. A second operation of the shear blade cuts off the leading end of the log and the shear blade returns back along the main frame to its starting position to repeat the cycle on another section of the log. The various splitting blades are shown in FIGS. 12-17.
In U.S. Pat. No. 5,711,357, Smith discloses an adjustable multi-wedge splitting head for a log splitting apparatus, equipped with a ram for axially advancing precut logs toward the splitting head in a horizontal direction. The apparatus includes a vertically oriented stationary post and a stationary triangular splitting wedge disposed between the post and the log to be split. The post holds upper and lower multiple splitting wedge assemblies, which can be slideably positioned on the post by hydraulic cylinder/piston units. The triangular splitting wedge severs a log into two pieces. The wedge assemblies then sever the initially produced two pieces into smaller pieces, the number of which corresponds to the number of blades in the assembly positioned to interact with the log. The splitting blades are best seen in FIGS. 3 and 4.
Smith, in U.S. Pat. No. 6,991,010, describes a splitting head for a log splitting apparatus that includes abutting primary and secondary splitting assemblies, each having a circular securing ring that holds wedge members having cutting edges directed toward the log. The cutting edges of the secondary assembly split into smaller pieces the pieces produced by the primary assembly. The system produces a bundle of elongated pieces of firewood in parallel array and wherein the center of the bundle has not been compressed. Note the circular cutting wedges of FIGS. 3-5.
In U.S. Pat. No. 7,104,295, Heikkinen et al. disclose a log splitting system that comprises a splitter box, having top, bottom and sidewalls, and open entrance and discharge ends. A first set of cutting blades secured adjacent to the entrance end divides the entrance end into at least two, first sections. A second set of cutting blades, secured adjacent to the first set of cutting blades and opposite the entrance end, further divides each splitter box's first section into at least two, second sections. A ram assembly with a force applying surface, moveable toward the splitter box's entrance end, contacts a log with the first set of cutting blades. The ram member's surface has a plurality of surface portions, each sized to fit into one of the splitter box's first section, to further contact the log, with the second set of cutting blades splitting the log into at least four pieces. Note the multiple blades shown in FIG. 1.
Heikkinen, in U.S. Pat. No. 7,104,296, describes a log splitting system that comprises a splitter box, having entrance and discharge sections, each with top, bottom and sidewalls, and open entrance and discharge ends. A first set of cutting blades in the entrance section divides that section into at least two, first sections. A second set of cutting blades in the discharge section further divides each first section into at least two, second sections. The entrance and discharge sections are hinged at the top and pivot apart for cleaning and service. A ram assembly with a force applying surface contacts a log with the first set of cutting blades. The ram member's surface has surface portions, each sized to fit into one of the splitter box's first section, to further contact the log with the second set of cutting blades, splitting the log into at least four pieces. Note the multiple blades shown in FIG. 14.
In U.S. Pat. No. 7,108,029, Albright discloses a wood splitting machine having a plurality of wedges of various sizes and configurations, radially attached to a rotational member mounted on the frame behind the log cradle. An operator can quickly and easily rotate the appropriate wedge into position, depending on the diameter of the log in the cradle to be split. The rotational member is hydraulically actuated such that the wedges rotate around the longitudinal axis of the machine with little effort for the operator. An alternate embodiment provides that the rotational member is manually rotated, such that the wedges are rotated around the longitudinal axis of the machine by the hand of the operator. Note the various cutting wedges of FIG. 3.
Applicants have invented a splitting blade assembly that overcomes many of the short comings of the blades of the current technologies outlined above.